Control of alternating-current motors.



No. 682,093. Patented Sept. 3, I90I. R. D. DE LIGNIERES.

CONTRDL 0F ALTERNATING CURRENT IGTUBS. (Appmtim mod In. 29, 1901.) (noIndem e sham-sheet n.

Illllll 1 d/K ,B www. ym WQ No. 682,093. Patented Sept. 3, I90I. R. D.DE LIGNIERES.

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No. 682,1193. Patented sept. 3, lsol. n. n. DE Llsmtnas.

CONTROL UF ALTERNATING CURRENT IUTORS. (Appuwion mod n. 2n, 1901.)

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ne. 682,093. Patented sept. a, tam. n. n. ne nemesis.

CONTROL OF ALTERNATING CURRENT MOTORS.

(Appuenien med im. sa, 1901.) (No Model.) 9 Shoots-Sheet 8.

lllulllt- -lmlllmlL- No. 682,093. l Patented sept. a, 190|.

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CONTROL 0F ALTERNATING CURRENT IUTORS..

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No. 682,093. Pannen sept. 3, leol. n. n. ne Lmmenes.

CONTROL 0F ALTERNATING CURRENT MUTOHS.

(Applcttion- Med In'. 22. 1901.)

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N0. 682,093. Patented Sept. 3, I9OI. R. D. DE LIGNIERES.

CONTROL OF ALTERNATING CURRENT MOTORS.

(Appumion med nu. 22, 1901.)

(No Model.) 9 Sheets-Sheet 9.

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IIIHII lill! lllllllllllll 50629566666/ lge/ufff' [W ren. de Irrgang/e6gmk/M ely kro UNITED STATES PATENT OEEICE.

RENE DAssY DE LIGNIERES, oF PARIs, FRANCE.

CONTROL OF ALTERNATING-CURRENT MOTORS.

SPECIFICATION forming part of Letters Patent No. 682,093, datedSeptember 3, 1901.

Application filed March 22, 1901. Serial No. 52,433. (No model.)

To all whom t m/cty concern:

ABe it known that I, REN DAssY DE LIG- NIRES, engineer, a citizen of theFrench Republic, residing at Paris, France, (whose postoftice address is69 Avenue de Vagram, in the said city,) have invented certain new anduseful Improvements in the Control of Alternating-Current Motors, ofwhich the following is a specification.

This invention has for its object a device the purpose of which is toenable the working speed of single-phase or polyphase alternate-currentmotors being varied as desired from zero to double the normal workingspeed while they are running by shifting a sliding contact-bar overmetallic contacts.

This invention further permits of the motor being stopped suddenlywithout it being necessary to reverse the current to reverse thedirection of the rotation of the armature, a practice which is alwaysdangerous and injurious to the good preservation of motors.

In order that this invention may be clearly understood, I will describeit with reference to the accompanying drawings, first, the generalprinciples on which this invention is based, and then the detailedarrangements of 'an application of my invention.

Figure l of the drawings is a diagrammatic view of the whole arrangementand working connections. Figs. 2 to 23 show diagrammatically the variouscircuits effected by shifting the aforesaid sliding contact-bar over thevarious fixed contacts of the switchboard. Fig. 24 is a diagram of thevarious speeds obtained by shifting the said sliding contactbar. Fig. 25shows the switchboard with its metallic contacts and the slidingcontact-bar. Fig. 26 shows, partly in section, a motor con. structedaccording to my invention. Fig. 27 is a detail showing on a larger scalethe means for supplying current from the source of electrical energy tothe inducing-field.

The invention is based on the following principles: If in a monophase orpolyphase alternate-current motor both the number of poles and thevoltage of the current supplied to the motor are caused to vary, it isobvious that, first, the working speed will increase when the number ofpoles diminishes,and,second,in consequence of the more or less highvoltage the value of the available couple will vary aboutproportionately to the square of the voltage.

The motor, as shown in Fig. 2G, consists of an armature a, keyed on ashaft b, mounted in bearings on pedestals ln. On the shaft l) is looselymounted the inducing-field c, together with contact-rings cl e f g, (thenumberof which depends upon the maximum number of poles of the motor,)and a toothed wheel h, gearing with a wheel i, keyed on the shaft of acontinuous-current motorj, which is capable of driving the whole of, theaforesaid parts. In Fig. l the motor j is represented diagrammaticallyas a series-wound motor with variable resistances 7c. lis the source ofenergy for supplying current to the motor.` When the armature revolvesat its normal speed, the inducing-field c remaining stationary, therelative speed between the field created by the inducing and inducedcircuits is equal to the absolute speed of the armature. If while thearmature is running at its normal speed the motor j is energized by acurrent, this latter will revolve and cause the inducing-field c torevolve. Owing to the movement of the inducing-held the coils of thearmature a do not act with the same relative speed as the lines of forceof the inducing-field, and according to a known law the absolute speedof the armature will vary by a number of revolutions equal to that ofthe inducingfield. If the rotation of the inducing-field be in the samedirection as that of the armature, the relative speed decreases for aninstant, but the couple increases, and the armature 4seeks to resume therelative speed it had previously, and consequently its absolute speedwill be increased by a number of revolutions equal to that of theinducing-field. Likewise if the rotation of the inducing-field be in adirection opposite to that of the armature the relative speed increases,but the couple decreases, and the armature has a tendency to resume itsrelative speed, and consequently its number of revolutions decreases bya number of revolutions nearly equal to that of the inducing-field.

The following table will show the relation between the speed of theinducing-field and that of the armature, taking the speed of theinducing-ield as positive when it revolves in a direction opposite tothat of the armature IOO and as negative when the said inducing-fieldrevolves in the same direction as the armature: v

By the like reasoning it will be seen that if the armature be at restand the inducing-field be rotated with the angular velocity which thearmature possesses when running at the ordinary speed the latter wouldrevolve in one direction or the other, according to the rotation of thearmature, Whatever the current sup plied may be.

In Figs. 1 and 25 is represented a switchboard to which are attachedcontacts, the number and position of which may vary, according tocircumstances. A sliding contactbar m, Figs. l and 25, moved over thesaid fixed contact by means of an endless screw q, permits of connectingin parallel, in series, or in multiple series the elements of the sourceof energy in the case under consideration, the low-tension circuits ofseveral transformers, or any number of sections of one and the sametransformer. In order not to complicate the drawings, only two circuitsof transformers n o, Figs. 1 and 2 to 23, are shown. The arrangementcomprises also the motor shown diagrammatically in Fig. 1.

The inducing-field c is divided into as many sections as the maximumnumber of poles of the motor. The beginning of one section and the endof the next adjacent one are connected together to one of the rings d,e, f, or g. As these rings revolve at the same time as theinducing-field, the connections may be rigid. Rubbing-contacts p (shownin Fig. 27) supply the current from the sections of the transformers no, Fig. l, to the lsections of the inducing-field through the medium ofthe rings d cfg. The drawings suppose that the maximum number of polesof the motor is four only. Consequently four rings d e f g are provided.It is evident that the invention is not limited to the number of poles,the number depending upon the design of the motor and upon theconditions which it has to fuliil.

The connections eiected successively by the sliding contact-bar m whenmoving from right to left over the contacts of the switchboard will nowbe described.

Figs. 2, 3, 4, and 5 show the results of the passage of the slidingcontact-bar on the first nine contacts. The contacts 1 and 9 beinginactive or unconnected, the moving of the sliding contact-bar over thecontacts 2, 3, and

4, Figs. 2, 3, and 4, successively switches in and couples in parallelthe partial coils of the two transformers o and n. The current from thepositive poles of the transformers enters the brushes d and f and thecurrent from the negative poles enters the brushes e and g. When all thecoils-are switched in, Fig. 5, the voltage at the terminals of the motorwill be E and the motor works as a four-pole one. The switching in ofthe whole of the coils of the transformers is effected through contact5, while contacts 6, 7, and 8 effect the same connections as contacts 4,3, and 2, Figs. 4, 3, and 2, so Aas to cut out Without suddenness thecurrent that becomes equal to zero when contact 9 is reached beforealtering the connection for grouping in series the partial coils. Thegrouping in series of the partial coils is eected by moving the slidingcontact-bar m over contact-pieces 10 to 17. The current from thepositive pole of the coil n then iiows to the brush d and the currentfrom the negativepole of the coil o to the brush f, the negative pole ofthe coil n and l the positive pole of the coil o being connectedtogether. When all the coils are switched in the circuit, Fig. 13, thevoltage at the motor-terminals is equal to 2 E. While in the first casethe number of poles was four, in the second case it is two. Consequentlythe speed of the motor, which was, for instance, Vin the first case,will become 2 V in the second case. The motor will thus possess twonormal working speeds without it being necessary to introduceresistances in the circuit.

IOO

Figs. 14, 15, 16, and 17 show the result of the passage of the slidingcontact-bar m over the contacts 18, 19, 20, and 2l, with gradual supplyof current to the motor j, irst with all its resistances k switched inand then gradually cut out. It will be understood that this motor may bereplaced by a shunt on the principal motor or by any other means.

In Fig. 17 the motor j is supposed to be working at full speed, theresistances being switched o. This maximum speed will be equal to themaximum speed which the armature a can assume when the inducing-iield cremains stationary. This motor j drives -the inducing-field c, and thedirection of its rotation is such that the inducing-field c revolves inthe same direction as the armature. The speed of the armature will whenthe contact-bar m is on contact 21 be equal to 2 (2 V) or 4 V, and thenumber of poles not varying the normal speed of the armature would be 2V. This speed is doubled in consequence of the inducing-iield rotatingin the same direction and at the same speed as the armature.

Figs. 18 to 23 show the movement of the sliding contact-bar m on thecontacts 22 to 27 for effecting the `sudden stoppage of the armature aWhile running. This stoppage is effected by reversing the direction ofthe rotation of the inducing-iield-that is to say,

IIO

by causing it to revolve in a direction opposite to that ofthe armature.Figs. 18, 19, and 2O show the gradual stoppage of the motor j, whileFigs. 2l, 22, and 23, with the arrows pointing from right tov left, showthe setting in a motion ofthe inducing-field c in a direction oppositeto that of the armature a. In the hereinbefore-described example the mo-,torj is supposed to have been switched in the circuit only whenarmature a has attained the normal speed corresponding to the bipolararrangement of the motor; but the motion of the inducing-field may inaccordance with my invention be brought into action every time a normalspeed is attained, so that the armature may assume all the speedscomprised between zero and that equal to double the ordinary workingspeed.

In the hereinbefore-described example the switchboard may be providedwith contactpieces permitting of the inducing-field being set in motionas soon as the sections of the transformers are connected in paralleland the speed V, corresponding to the four-pole arrangement of themotor,has been attainedthat is to say, after contact 5 has been reached.

If it be supposed that the motor have a larger number of poles, theswitchboard may be provided with additional contacts forswitching in themotorj each time a normal speed is reached. It is evident that it wouldbe necessary for each working speed to introduce into the circuit of themotorj (which is supposed to be series-wound, but may be of another kindor replaced by any other means) resistances such that the speed to beimparted to the inducing-field c has for maximum the speed which is atthat moment the working speed of the armature ct. The stoppage isobtained when the auxiliary motor j is caused to rotate with a speedsuch that the inducing-field c reaches a speed equal to that of thearmature a and in the opposite direction.

Fig. 24 is a diagram showing the progressive speeds and the spontaneousstoppage etfected by the switchboard. On the abscissa are marked thetwenty-seven contacts of the switchboard, while the ordinates representthe speeds from zero to 4 V. On the sliding contact-bar leaving contact5, which supplies the full current to the four-pole motor, the

current is cut and afterward supplied gradually to the bipolararrangement. The speed is not reduced to zero because ot' the momentumdue to the motion of the motor and of the mechanical energy stored inthe mass of the armature which was running at its normal speed. As themanipulation required to move the sliding contact-bar over the fixedcontacts can be rapidly effected, the decrease attained in the speed isbut small.

Fig. 25 shows the switchboard, the sliding contact-bar m, and theendless screw q, on which the said sliding contact-bar moves, the screwbeing operated by a crank-handle o', fixed to one end thereof. m

Having now particularly described andascertained the nature of thisinvention and in what manner it may be performed, I declare what I claimis-- l. In a controller for alternating-current induction-motors, meansfor changing the number of poles of the motor and means for moving theinducing-field member in one direction or the other.

2. In a controller for alternating-current induction-motors, means forchanging the number of poles of the motor, means for moving theinducing-field member in one direction or the other, and means forvarying the voltage in the motor by connecting up therewith a greater orless number of convolutions of the secondary coils of a transformer.

3. In a controller for alternating-current induction-motors, means forchanging the number of poles of the motor, and an auxiliary motor formoving the inducing-field member in one direction or the other.

it. In a controller for alternating-current induction-motors, means forchanging the number of poles of the motor, means for varying the voltagein the motor by connecting up therewith a greater or less number ofconvolutions of the secondary coils of a transformen-@JL- and anauxiliary motor for moving the inducing-field member in one direction orthe other. In testimony whereof I have hereunto set my hand in presenceof two subscribing witnesses.

REN DASSY Dil LIGNIILES. Witnesses:

EDWARD l?. INIACLEAN, EMILE KLOTZ.

